#580 - Add Cassandra examples for optimistic locking.

cassandra/example/src/main/java/example/springdata/cassandra/optimisticlocking/BasicConfiguration.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package example.springdata.cassandra.optimisticlocking;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.domain.EntityScan;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * Basic {@link Configuration} to create the necessary schema for the {@link OptimisticPerson} table.
+ *
+ * @author Mark Paluch
+ */
+@SpringBootApplication
+@EntityScan(basePackageClasses = OptimisticPerson.class)
+class BasicConfiguration {
+
+}

cassandra/example/src/main/java/example/springdata/cassandra/optimisticlocking/OptimisticPerson.java

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+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package example.springdata.cassandra.optimisticlocking;
+
+import lombok.Data;
+
+import org.springframework.data.annotation.Id;
+import org.springframework.data.annotation.Version;
+import org.springframework.data.cassandra.core.mapping.Table;
+
+/**
+ * Simple domain object that declares properties annotated with Spring Data's {@code @Version} annotation to enable the
+ * object for optimistic locking.
+ *
+ * @author Mark Paluch
+ */
+@Data
+@Table
+public class OptimisticPerson {
+
+	@Id Long id;
+
+	@Version long version;
+
+	String name;
+
+}

cassandra/example/src/main/java/example/springdata/cassandra/optimisticlocking/OptimisticPersonRepository.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package example.springdata.cassandra.optimisticlocking;
+
+import org.springframework.data.repository.CrudRepository;
+
+/**
+ * Simple repository interface for {@link OptimisticPerson} instances.
+ *
+ * @author Mark Paluch
+ */
+public interface OptimisticPersonRepository extends CrudRepository<OptimisticPerson, Long> {}

cassandra/example/src/main/java/example/springdata/cassandra/optimisticlocking/SimplePerson.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package example.springdata.cassandra.optimisticlocking;
+
+import lombok.Data;
+
+import org.springframework.data.annotation.Id;
+import org.springframework.data.cassandra.core.mapping.Table;
+
+/**
+ * Simple domain object.
+ *
+ * @author Mark Paluch
+ */
+@Data
+@Table
+public class SimplePerson {
+
+	@Id Long id;
+
+	String name;
+
+}

cassandra/example/src/test/java/example/springdata/cassandra/auditing/AuditedPersonRepositoryTests.java

@@ -32,7 +32,7 @@ import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.test.context.junit4.SpringRunner;
 
 /**
- * Integration test showing the basic usage of {@link AuditedPersonRepository}.
+ * Integration test showing the basic usage of Auditing through {@link AuditedPersonRepository}.
  *
  * @author Mark Paluch
  */

cassandra/example/src/test/java/example/springdata/cassandra/optimisticlocking/OptimisticPersonRepositoryTests.java

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+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package example.springdata.cassandra.optimisticlocking;
+
+import static org.assertj.core.api.Assertions.*;
+
+import example.springdata.cassandra.util.CassandraKeyspace;
+
+import org.junit.Before;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.dao.OptimisticLockingFailureException;
+import org.springframework.data.cassandra.core.CassandraOperations;
+import org.springframework.data.cassandra.core.EntityWriteResult;
+import org.springframework.data.cassandra.core.UpdateOptions;
+import org.springframework.data.cassandra.core.query.Criteria;
+import org.springframework.test.context.junit4.SpringRunner;
+
+/**
+ * Integration test showing the basic usage of Optimistic Locking through {@link OptimisticPersonRepository}.
+ *
+ * @author Mark Paluch
+ */
+@RunWith(SpringRunner.class)
+@SpringBootTest(classes = BasicConfiguration.class)
+public class OptimisticPersonRepositoryTests {
+
+	@ClassRule public final static CassandraKeyspace CASSANDRA_KEYSPACE = CassandraKeyspace.onLocalhost();
+
+	@Autowired OptimisticPersonRepository repository;
+	@Autowired CassandraOperations operations;
+
+	@Before
+	public void setUp() {
+		repository.deleteAll();
+	}
+
+	/**
+	 * Saving an object using the Cassandra Repository will create a persistent representation of the object in Cassandra
+	 * and increment the version property.
+	 */
+	@Test
+	public void insertShouldIncrementVersion() {
+
+		OptimisticPerson person = new OptimisticPerson();
+		person.setId(42L);
+		person.setName("Walter White");
+
+		OptimisticPerson saved = repository.save(person);
+
+		assertThat(saved.getVersion()).isGreaterThan(0);
+	}
+
+	/**
+	 * Modifying an existing object will update the last modified fields.
+	 */
+	@Test
+	public void updateShouldDetectChangedEntity() {
+
+		OptimisticPerson person = new OptimisticPerson();
+		person.setId(42L);
+		person.setName("Walter White");
+
+		// Load the person because we intend to change it.
+		OptimisticPerson saved = repository.save(person);
+
+		// Another process has changed the person object in the meantime.
+		OptimisticPerson anotherProcess = repository.findById(person.getId()).get();
+		anotherProcess.setName("Heisenberg");
+		repository.save(anotherProcess);
+
+		// Now it's our turn to modify the object...
+		saved.setName("Walter");
+
+		// ...which fails with a OptimisticLockingFailureException, using LWT under the hood.
+		assertThatExceptionOfType(OptimisticLockingFailureException.class).isThrownBy(() -> repository.save(saved));
+	}
+
+	/**
+	 * This tests uses lightweight transactions by leveraging mapped {@code IF} conditions with the {@code UPDATE}
+	 * statement through {@link CassandraOperations#update(Object, UpdateOptions)}.
+	 */
+	@Test
+	public void updateUsingLightWeightTransactions() {
+
+		SimplePerson person = new SimplePerson();
+		person.setId(42L);
+		person.setName("Walter White");
+
+		operations.insert(person);
+
+		EntityWriteResult<SimplePerson> success = operations.update(person,
+				UpdateOptions.builder().ifCondition(Criteria.where("name").is("Walter White")).build());
+
+		assertThat(success.wasApplied()).isTrue();
+
+		EntityWriteResult<SimplePerson> failed = operations.update(person,
+				UpdateOptions.builder().ifCondition(Criteria.where("name").is("Heisenberg")).build());
+
+		assertThat(failed.wasApplied()).isFalse();
+	}
+
+}